Gone fishing open thread

“…why do brine pools and salt domes persist?”
There is no force to motivate ‘spontaneous mixing’. The brine is denser than the seawater. Gravity / lack of buoyancy / Archimedes’ Principle apply.
There is no semi-permeable membrane (permeable to solvent but not solute) so ‘osmosis’ does not apply.
Diffusion is a very slow and short-range process compared to ‘overturning circulation’, which can only occur when a denser fluid lies *above* a less dense fluid.

It is complicated. Radiation is (more or less) a fourth-power-of-temperature (in Kelvin of course) phenomenon, meaning as dirt cools its radiation drops dramatically, but not only that, peak wavelength changes. A “blackbody” presumably radiates on all wavelengths up to its cutoff; but carbon dioxide has a quantum energy state that compels it to radiate, or capture, at a specific wavelength. It is what makes a carbon dioxide laser possible.
The implication is that when temperature goes below that which would produce that wavelength, carbon dioxide simply ceases to radiate. It is not a gradual thing, or so it seems to me. In my effort to quantify this effect I found an informative website that goes into this topic in great detail, also explaining the exact mechanism by which water vapor (primarily) and carbon dioxide interact with electromagnetic radiation at various wavelengths.
http://mysite.du.edu/~etuttle/weather/atmrad.htm
So the rapid drop in temperature is initially just seeking an equilibrium for the night — removing the solar heating of the surface which maintains an *imbalance* between dirt and air. Convection is doubtless the principle cooler of dirt and could easily be tested by placing a box with an IR transparent cover over the dirt, preventing convection, and see if its cooling rate is changed. A remote reading IR thermometer could see through the cover (Saran wrap maybe?).
Convection is a heat engine and once the differential between dirt and air is reduced, that particular engine stops, leaving radiation as the sole remover of further heat from dirt. Of course, the water vapor and CO2 in the air will re-radiate right back onto the dirt so there’s going to be a lapse rate with altitude, farther from warm dirt and closer to cold sky and “top of atmosphere”.
This is probably the two rates of cooling that you observe, with dew point being a third.
I’m seriously thinking about getting one of those imaging thermometers such as Fluke VT04. You can see it in operation on a series of videos made by Anthony Watts, see above under Climate FAIL Files, then Al Gore and Bill Nye. The imaging thermometer clearly shows that glass is opaque to longwave infrared and thus the energy from the heat lamp never reaches the CO2 in the jar.
At night, it will “see” the source of longwave infrared.
Interestingly, googling for night scenes shows no sea or soup of infrared emitted by the atmosphere. If the mean distance of infrared was 10 meters as is sometimes claimed, you’d lose 50 percent of your image in only 10 meters to a “haze” of background radiation from the atmosphere itself. But that seems not to be the case. The implication of that is that convection is paramount and infrared capture and re-radiation is almost non-existent near the earth’s surface because otherwise you would plainly see it in one of these infrared imagers.